KR20170117637A - Protective coating film composition for automotive glass and manufacturing method therefrom - Google Patents

Abstract

The present invention relates to a coating film composition for protecting an automobile glass comprising a monofunctional urethane acrylate oligomer, a monofunctional acrylate monomer, a polyfunctional acrylate monomer, and a photoinitiator, and a process for producing a coating film for protecting an automobile glass using the same.
The coating film composition for protecting an automobile glass according to the present invention has excellent light transmittance, improved impact resistance and durability, can be cured in a short time, and can be uniformly applied to an inclined and curved vehicle front glass.

Description

TECHNICAL FIELD The present invention relates to a coating composition for protecting glass for automobiles and a coating film using the same,

The present invention relates to a coating film composition for protecting an automobile glass and a coating film using the same, and more particularly, to a method for manufacturing a coating film for protecting an automobile glass, which is improved in impact resistance and durability while being transparent and hardened in a short time.

Automobile glass is known to use synthetic glass and tempered glass depending on safety in case of emergency. This is designed so that only cracks occur when an impact is generated from the outside, so that injuries caused by glass fragments can be prevented.

As an example, the windshield of an automobile can use mainly laminated synthetic glass for the protection of the driver. The automotive windshield can be manufactured by inserting a film such as PVB (Poly Vinyl Butyrate) between two glasses having a predetermined thickness and pressing the glass with the film at high temperature and high pressure.

However, the automotive windshield may easily crack due to the winter temperature difference or the foreign matter coming from the outside, and it is necessary to fill the cracked or broken part with the adhesive or to replace the automobile windshield in severe cases .

To solve this problem, a glass protective film suitable for protection of display glass such as building materials, automobile window glass, and flat panel display has been proposed. Japanese Patent Application Laid-Open No. 10-2004-066711 discloses a film having a hard coat layer for protection of automobile glass.

However, when the lens is attached to a curved portion such as an automobile windshield, friction noise due to the wrinkled surface shape may occur during wiper operation, and the film may be peeled off due to poor durability during long-term use.

On the other hand, there is a method of directly applying a protective film instead of attaching the film to a curved automobile windshield. This can be applied by using a commercialized acrylic resin. The acrylic resin is effective for increasing bonding strength with an automobile windshield. However, if the acrylic resin contains an acrylic resin, the acrylic resin may be insufficient to prevent cracking of the glass from external impacts.

Furthermore, when a thicker coating film is prepared in order to prevent cracking from external impact, it may be effective in preventing cracking of the glass, but this may cause deterioration of light transmittance and non-uniformity of thickness.

In addition, since the coating film is difficult to cure within a short time, the coating solution can be cured in a state where the coating film is flowed down by the inclined front glass of the automobile during the curing step, and the coating film produced thereby can lower the visibility of the driver.

Japanese Patent Application Laid-Open No. 10-2004-066711

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a resin composition which is excellent in light transmittance, has improved impact resistance and durability, is cured in a short time, and can be uniformly applied to an inclined and curved automobile windshield And to provide a coating composition for protecting glass for automobiles.

Another object of the present invention is to provide a method for manufacturing a coating film for protecting glass for automobiles using a coating film composition for protecting glass for automobiles.

In order to achieve the above object, a coating film composition for protecting an automobile glass according to an embodiment of the present invention includes a monofunctional urethane acrylate oligomer, a monofunctional acrylate monomer, a polyfunctional acrylate monomer, and a photoinitiator.

In the coating film composition for protecting an automobile glass according to an embodiment of the present invention, the monofunctional urethane acrylate oligomer has a hydroxyl group (-OH) at the terminal and has a main chain of an ester main chain, an ether main chain or a mixed structure thereof, The molecular weight may be from 1,000 to 30,000.

In the coating film composition for protecting an automobile glass according to an embodiment of the present invention, the monofunctional urethane acrylate oligomer is contained in an amount of 30 to 75 parts by weight, the monofunctional acrylate monomer is contained in an amount of 5 to 50 parts by weight, 0.1 to 10 parts by weight of the polyfunctional acrylate monomer, and 0.1 to 10 parts by weight of the photoinitiator.

In the coating film composition for protecting an automobile glass according to an embodiment of the present invention, the coating film composition may further comprise a silane coupling agent represented by the following Formula 1:

[Chemical Formula 1]

Wherein X is a linear or branched C1 to C12 hydrocarbon group or a cyclic C3 to C20 hydrocarbon group having only one or two or more acryl groups and each of R ₁ to R ₃ is independently C1- C5 alkyl.]

The present invention also includes a method for producing a coating film for protecting glass for automobiles using the above-mentioned coating film composition.

The method for manufacturing a coating film for protecting an automobile glass according to an embodiment of the present invention includes the steps of a) forming a coating film by spraying the coating film composition onto a transparent substrate, and b) curing the coating film by ultraviolet rays or electron beams.

In the method for manufacturing a coating film for protecting an automobile glass according to an embodiment of the present invention, the thickness of the cured coating film may be 25 to 1000 mu m.

The coating film composition for protecting an automobile glass according to the present invention comprises a monofunctional urethane acrylate oligomer, a monofunctional acrylate monomer, a polyfunctional acrylate monomer, and a photoinitiator to prevent cracking of an automotive windshield due to an external physical impact And the transparency of the automotive windshield due to the coating can be prevented from deteriorating.

In addition, the coating film composition for protecting an automobile glass according to an embodiment of the present invention further includes at least one compound selected from alkoxysilanes and nanoparticles, so that mechanical properties such as durability and stretchability can be increased.

In addition, the coating film composition for protecting an automobile glass according to an embodiment of the present invention can improve dimensional stability, coatability and thickness uniformity.

In addition, the coating film composition for protecting an automobile glass according to an embodiment of the present invention can prevent uneven adhesion and whitening with the automotive windshield.

Hereinafter, the present invention will be described in detail. The following embodiments and drawings are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. In addition, unless otherwise defined in the technical and scientific terms used herein, unless otherwise defined, the meaning of what is commonly understood by one of ordinary skill in the art to which this invention belongs is as follows, A description of known functions and configurations that may unnecessarily obscure the gist of the present invention will be omitted.

In describing the present invention, the term "oligomer" means a low molecular weight polymer compound having a weight average molecular weight of 1,000 to 30,000. As an example, the oligomeric compound may be a liquid at room temperature and at atmospheric pressure.

In describing the present invention, the term "monomer" refers to a low molecular weight constituent unit capable of participating in a polymerization reaction to form a polymeric material. In one example, the weight average molecular weight of the monomeric compound may preferably be less than 1,000, more preferably less than 750.

In describing the present invention, the term "monofunctional monomer" means a monomer having one polymerizable group. For example, the monofunctional monomer may have an acrylate group.

In describing the present invention, the term "multifunctional monomer" means a monomer having two, three or more polymerizable groups. For example, the polyfunctional monomer may have one acrylate group and one vinyl ether group.

In the context of the present invention, the term "alkyl" means all possible variants for each number of carbon atoms in the alkyl group, for example methyl, ethyl, profile; When there are 4 carbon atoms: n-butyl, isobutyl, and t-butyl; Pentyl, 1,1-dimethyl-propyl, 2,2-dimethylpropyl and 2-methyl-butyl.

In describing the present invention, the term "transparent" means that the intensity before passing through a transparent medium in a visible light region is I0, and the intensity after passing through the transparent medium is I1, / I0) x 100) is 50% or more, preferably 60% or more, the permeation medium is said to be transparent.

The present applicant has studied a coating film composition for protecting an automobile glass which can prevent cracking of an automobile windshield due to external impact while maintaining optical transparency. As a result, it has been surprisingly found that the impact resistance and durability are improved, A coating film composition which is cured has been developed and has been filed.

Hereinafter, the present invention will be described in detail.

The coating film composition for protecting an automobile glass according to the present invention comprises a monofunctional urethane acrylate oligomer, a monofunctional acrylate monomer, a polyfunctional acrylate monomer, and a photoinitiator.

The monofunctional urethane acrylate oligomer according to an embodiment of the present invention may have a hydroxyl group (-OH) at the terminal.

As a preferred example, the number of the hydroxy groups may be one to two, but the present invention is not limited thereto.

The hydroxy group according to an embodiment of the present invention may form a hydrogen bond between the monofunctional urethane acrylate oligomers, thereby improving the crosslinking density of the coating layer. Accordingly, the coating film composition according to the present invention can increase the mechanical properties such as hardness and adhesion force, and can have excellent light transmission characteristics.

More specifically, when the number of the hydroxy groups is one according to an embodiment of the present invention, the coating film composition according to the present invention may be preferable in terms of higher hardness and binding force, but the present invention is not limited thereto.

In the coating film composition for protecting an automobile glass according to an embodiment of the present invention, the monofunctional urethane acrylate oligomer may have a main chain of an ester main chain, an ether main chain or a mixed structure thereof.

As a preferred example, the monofunctional urethane acrylate oligomer may include reactive end groups and urethane linking groups in the main chain component such as polyether, polyester, polycarbonate and the like.

The main chain of the monofunctional urethane acrylate oligomer according to an embodiment of the present invention is selected from the group consisting of polyether diol, hydrocarbon diol, polycarbonate diol, polyacrylate polyol (hydroxy functional acrylic polymer) and polycaprolactone diol Or more diol.

In a specific and non-limiting example, the main chain component is a polyether diol having a low viscosity at the same concentration in terms of the ability to minimize the amount of solvent used in forming an automotive glass coating film, May be preferable.

The polyether diol according to one embodiment of the present invention may be selected from the group consisting of polyethyleneglycol, polypropyleneglycol, polytetramethyleneglycol, polyhexamethyleneglycol, polyheptamethyleneglycol, polydecamethyleneglycol, two or more ion- Type compound or the like by ring-opening copolymerization, but the present invention is not limited thereto.

In a specific and non-limiting example, the ion-polymerized cyclic compound is selected from the group consisting of ethylene oxide, propylene oxide, butene-1-oxide, isobutene oxide, 3,3'-bischloromethyloxetane, tetrahydrofuran, 2- But are not limited to, methyl ethyl ketone, methyl tert-butyl ether, methyl tert-butyl ether, methyl tetrahydrofuran, 3-methyltetrahydrofuran, dioxane, trioxane, tetraoxane, cyclohexene oxide, styrene oxide, epichlorohydrin, glycidyl methacrylate, May include cyclic ethers such as carbonate, butadiene monoxide, isoprene monoxide, vinyl oxetane, vinyl tetrahydrofuran, vinyl cyclohexene oxide, phenyl glycidyl ether, butyl glycidyl ether, glycidyl benzoate and the like have.

In another specific, non-limiting example, the two or more ion-polymerized cyclic compounds are selected from the group consisting of tetrahydrofuran and propylene oxide , tetrahydrofuran and 2-methyltetrahydrofuran , tetrahydrofuran and 3-methyltetrahydrofuran , tetra A binary copolymer obtained by a combination of hydrofuran and ethylene oxide , propylene oxide and ethylene oxide , or ethylene oxide and butene-1-oxide ; Or a ternary copolymer obtained by a combination of tetrahydrofuran, ethylene oxide and butene-1-oxide, and the like.

In another specific, non-limiting example, a cyclic imine such as ethyleneimine with one of the ion-copolymerized cyclic compounds; cyclic lactones such as? -propiolactone and glycolic acid lactide; Or polyether diol obtained by ring-opening copolymerization of dimethylcyclopolysiloxane. At this time, the ring-opened copolymer of the ion-polymerized cyclic compound may be a random copolymer or a block copolymer, but the present invention is not limited thereto.

In the coating film composition for protecting an automobile glass according to an embodiment of the present invention, it is preferable that the monofunctional urethane acrylate oligomer has a weight average molecular weight of 1,000 to 30,000 in consideration of improvement in binding force, tensile strength, hardness, It is more preferable that the weight average molecular weight is 10,000 to 30,000, but the present invention is not limited thereto.

If the monofunctional urethane acrylate oligomer according to an embodiment of the present invention has a weight average molecular weight of less than 1,000, the elasticity may be too low to cause cohesive failure. If the monofunctional urethane acrylate oligomer is more than 30,000, the viscosity may increase, Which may cause a non-uniform coating film to be formed on the automobile windshield, thereby hindering the driver's view.

Also, in the coating film composition for protecting an automobile glass according to an embodiment of the present invention, the monofunctional urethane acrylate oligomer may be 30 to 75 parts by weight, preferably 40 to 75 parts by weight, , And more preferably 45 to 65 parts by weight.

If the content of the monofunctional urethane acrylate oligomer according to an embodiment of the present invention is less than 30 parts by weight based on 100 parts by weight of the coating composition, the content of the acrylate monomer may increase to cause curing shrinkage. If it exceeds the weight part, the degree of hardening and the hardness may be lowered.

In the coating film composition for protecting an automobile glass according to an embodiment of the present invention, the monofunctional acrylate-based monomer may be a material that imparts durability to the coating film composition, and preferably includes the monofunctional urethane acrylate oligomer It may serve to maintain the viscoelasticity and adjust the viscosity to improve the coating property of the coating film composition according to the present invention.

The monofunctional acrylate monomer according to an embodiment of the present invention may be preferably a monofunctional acrylate monomer. This can prevent non-uniform adhesion with the transparent substrate during the formation of the coating film, smooth the surface shape of the coating film, increase the light transmittance, and prevent whitening occurring during the curing process after the coating film is formed.

In a specific, non-limiting example, the monofunctional acrylate monomer is selected from the group consisting of ethyl acrylate, methyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, butyl acrylate, isobutyl acrylate, , 2-ethoxyethyl (meth) acrylate, isodecyl (meth) acrylate, 2-dodecylthioethyl methacrylate, octyl acrylate, isooctyl acrylate, 2-methoxyethyl acrylate, (Meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, isooctyl (meth) acrylate, isodecyl (Meth) acrylate, ethoxy-ethoxy (meth) acrylate, phenoxyethyl (meth) acrylate, octadecyl methacrylate, isobonyl Butyl acrylate, 2-acrylic acid 2 - may be ((butylamino) carbonyl) oxyethyl ester of a monofunctional monomer, such as one-morpholin-acryloyl.

In the coating film composition for protecting an automobile glass according to an embodiment of the present invention, the monofunctional acrylate monomer may be used in an amount of 5 to 50 parts by weight, preferably 10 to 45 parts by weight, Preferably 15 to 35 parts by weight.

If the content of the monofunctional acrylate monomer according to an embodiment of the present invention is less than 5 parts by weight based on 100 parts by weight of the coating composition, the curing rate may be low or the storage elastic modulus may be too low to cause cohesive failure. If it exceeds 50 parts by weight, curing shrinkage may be severe and the coating property may be lowered.

In the coating film composition for protecting an automobile glass according to an embodiment of the present invention, it is preferable that the above-mentioned polyfunctional acrylate-based monomer is used as a 2 to 4 functional acrylate-based monomer. This can increase the shear strength together with the above monofunctional urethane acrylate oligomer and monofunctional acrylate monomer, and can prevent insufficient peeling.

As specific and non-limiting examples, the polyfunctional acrylate monomer may be selected from the group consisting of 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6- Acrylate, ethylene glycol di (meth) acrylate, bisphenol A-ethylene glycol diacrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (Meth) acrylate, dicyclopentanyl di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, neopentyl glycol di Acrylate, di (meth) acrylate modified with lactone, dicyclopentenyl (meth) acrylate, ethylene oxide modified di (meth) acrylate, bis (2-hydroxyethyl) (Meth) acrylate, dimethylolcyclohexane diacrylate, ethylene oxide modified hexahydrophthalic acid diacrylate, tricyclodecane dimethanol acrylate, neopentyl glycol modified (meth) acrylate, Bifunctional monomers such as trimethylolpropane diacrylate, adamantanediacrylate and the like; (Meth) acrylate such as trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri Trifunctional monomers such as tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, glycerol tri ; Or tetrafunctional monomers such as diglycerin tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, and ditrimethylol propane tetra (meth) acrylate. These monomers may be used alone or in combination of two or more. have.

In the coating film composition for protecting an automobile glass according to an embodiment of the present invention, the polyfunctional acrylate monomer may be used in an amount of 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, , And more preferably 1 to 3 parts by weight.

If the content of the polyfunctional acrylate monomer according to an embodiment of the present invention is less than 0.1 parts by weight based on 100 parts by weight of the coating composition, mechanical properties such as hardness and tensile strength may be deteriorated. If the content is more than 10 parts by weight Permeability, binding force, elongation and the like may be lowered.

In the coating film composition for protecting an automobile glass according to an embodiment of the present invention, the above-mentioned photoinitiator may be enough to sufficiently progress the inside and the surface hardening of the coating film within a short time, and if it is known in the art, It does not.

In a specific, non-limiting example, the photoinitiator is selected from the group consisting of benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, Dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 4-methylacetophenone, 4-methylacetophenone, 2-methyl-1-phenylpropan-1-one, poly [2-hydroxy-2-methyl-1- [4- (Methylvinyl) phenyl] propan-1-one], 4-hydroxycyclophenyl ketone, 1-hydroxycyclohexyl phenyl ketone, (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4-diaminobenzophenone , 4,4'-diethylaminobenzophenone, dichlorobenzophe , Anthraquinone, 2-methyl anthraquinone, 2-ethyl anthraquinone, 2-t-butyl anthraquinone, 2-amino anthraquinone, 2-methyl thioxanthone, , 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethyl ketal, diphenyl ketone benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoic acid ester, 2,4,6-trimethyl Benzophenone, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, fluorene, triphenylamine, carbazole, and the like.

The photoinitiator may be commercially available products such as Esacure KIP 100 from Lamberti Spa, Gallarate, Italy, Irgacure 651 from Ciba-Geigy, Lautertal, Germany, 2- or 3-methylbenzophenone of Aldrich Co., Milwaukee, Wis., USA; Darocur 1173 of Ciba; Igacure 184 of Ciba; Igacure 907 from Ciba, Igacure 1700 from Ciba, etc. These can be used alone or in combination of two or more.

In the coating film composition for protecting an automobile glass according to an embodiment of the present invention, the photoinitiator may be used in an appropriate range in consideration of the radiation property, intensity, content of each component, etc. of the light source. To 10 parts by weight.

In the coating film composition for protecting an automobile glass according to an embodiment of the present invention, the coating film composition may further comprise a silane coupling agent represented by the following formula (1)

[Chemical Formula 1]

Wherein X is a linear or branched C1 to C12 hydrocarbon group or a cyclic C3 to C20 hydrocarbon group having only one or two or more acryl groups and each of R ₁ to R ₃ is independently C1- C5 alkyl.]

In a specific, non-limiting example, the silane coupling agent may be an alkoxysilane compound, and more specifically, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, phenyltrimethoxysilane, methyltriethoxy Silane, phenyltriethoxysilane, dimethyldimethoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, dimethyldiethoxysilane, diphenyldiethoxysilane, methylphenyldiethoxysilane, trimethylmethoxysilane, and trimethylethoxysilane May be selected.

The silane coupling agent according to an embodiment of the present invention may be combined with the monofunctional urethane acrylate oligomer, the monofunctional acrylate monomer, the polyfunctional acrylate monomer, and the photoinitiator to increase the elasticity, releasability, and impact resistance . In addition, the silane coupling agent can prevent aggregation of nanoparticles to be described later.

In the coating film composition for protecting an automobile glass according to an embodiment of the present invention, the silane coupling agent can be used in an appropriate range in consideration of tensile strength, elongation, impact resistance, adhesive strength, and the like.

The silane coupling agent according to an embodiment of the present invention may be used in an amount of 1 to 30 parts by weight, preferably 1 to 15 parts by weight, more preferably 1 to 10 parts by weight, The present invention is not limited to the weight part category of the silane coupling agent. At this time, when the above-mentioned coating film composition satisfies the above-mentioned category, it can increase the adhesive force with automobile glass.

In the coating film composition for protecting an automobile glass according to an embodiment of the present invention, the coating film composition may further include nanoparticles, but the present invention is not limited thereto.

The nanoparticles according to an embodiment of the present invention may be titania or zirconia having a plurality of (meth) acrylic groups on the surface of the particles. When used together with the monofunctional urethane acrylate oligomer, the monofunctional acrylate monomer, the polyfunctional acrylate monomer, the photoinitiator, and the silane coupling agent, the light transmittance, the tensile strength, and the impact resistance can be increased.

In detail, the nanoparticles may be titania or zirconia that is surface-modified with at least one compound selected from a photocurable triazine monomer compound and an acrylate compound, but the present invention is not limited thereto.

As a specific, non-limiting example, the photo-curable triazine monomer compound may be prepared by reacting 2,4,6-triaminotriazine with an amino group of 2-, 4-, and / And one or more functional groups may be combined.

As a specific, non-limiting example, the acrylate compound used in the modification of the nanoparticles may be acryloxy (C1-C6 alkyl) tri (C1-C6 alkoxy) silane, more specifically 3- Methoxysilyl) propyl methacrylate, and the like.

In another specific, non-limiting example, the nanoparticles may have an average particle size of 10 to 200 nm, preferably 50 to 100 nm. This can form a coating film suitable for use in protecting an automobile glass according to the present invention, and may be more preferable for spraying the coating film composition according to the present invention onto a transparent substrate.

The nanoparticles according to an embodiment of the present invention may be used in an appropriate range in consideration of light transmittance, tensile strength, impact resistance, uniformity of thickness, etc., and 1 to 10 parts by weight May be preferable in terms of improvement in hardness and impact resistance, and more preferably 3 to 7 parts by weight.

In the coating film composition for protecting an automobile glass according to an embodiment of the present invention, the coating film composition may further include a solvent. This can improve the viscosity, uniformity of thickness, and coatability of the coating film composition according to the present invention.

The solvent according to an embodiment of the present invention may be one or more selected from the group consisting of a hydrocarbon-based solvent and an acetate-based solvent, but the present invention is not limited thereto.

As specific and non-limiting examples, the hydrocarbon-based solvent may be a substance capable of dissolving the above-mentioned acrylate monomer, and examples thereof include toluene, benzene, cyclohexane and the like.

As a specific, non-limiting example, the acetate-based solvent may be a material that lowers the viscosity of the coating film composition and uniformly mixes the monofunctional urethane acrylate oligomer described above in the coating film composition. For example, the acetate solvent includes ethyl acetate, propyl acetate, butyl acetate, amyl acetate, hexyl acetate, ethyl carbitol acetate and the like.

In the coating film composition for protecting an automobile glass according to an embodiment of the present invention, the solvent is preferably 5 to 60 parts by weight, more preferably 10 to 50 parts by weight based on 100 parts by weight of the coating composition, The present invention is not limited thereto.

In the coating film composition for protecting an automobile glass according to an embodiment of the present invention, the ratio of the hydrocarbon-based solvent to the acetate-based solvent is preferably 10 to 50 parts by weight based on 100 parts by weight of the hydrocarbon-based solvent can do. This may be preferable in view of the thickness control of the coating film according to the present invention and the ease of spraying, but the present invention is not limited to the ratio of the hydrocarbon-based solvent and the acetate-based solvent.

In the coating film composition for protecting an automobile glass according to an embodiment of the present invention, when the solvent satisfies the ratio of the weight part to the hydrocarbon-based and acetate-based solvent, the coating film composition according to the present invention may have a coating film thickness uniformity Can be further improved.

In addition, the present invention includes a method for manufacturing a coating film for protecting an automobile glass using the coating film composition for protecting an automobile glass.

The method for manufacturing a coating film for protecting an automobile glass according to an embodiment of the present invention includes the steps of a) forming a coating film by spraying the coating film composition onto a transparent substrate, and b) curing the coating film by ultraviolet rays or electron beams.

The transparent substrate according to an embodiment of the present invention may be a material that can be applied to an automobile glass. Specific examples of the transparent substrate include synthetic glass and tempered glass. However, the present invention is not limited thereto.

In the method for manufacturing a coating film for protecting an automobile glass according to an embodiment of the present invention, in the step a), injection may be performed using compressed air.

As a specific and non-limiting example, the spraying method may include spray coating, flow coating, and the like.

The spray coating method according to an embodiment of the present invention may be preferable in terms of coating the coating film composition to a curved automobile glass to a uniform thickness. In addition, the spray coating method is more preferable because it can perform coating only on automobile glass except automobile exterior materials such as a roof of an automobile and an automobile A pillar, but the present invention is not limited to the coating method.

In the method for manufacturing a coating film for protecting an automobile glass according to an embodiment of the present invention, the thickness of the cured coating film after the step b) may be preferably 25 to 1000 탆 in terms of impact resistance and transparency, May be 100 to 500 탆, but the present invention is not limited thereto.

In the method for manufacturing a coating film for protecting an automobile glass according to an embodiment of the present invention, the steps a) and b) may be repeated two or more times in order for the cured coating film to have an impact resistance and a uniform thickness. The present invention is not limited thereto.

In the method for manufacturing a coating film for protecting an automobile glass according to an embodiment of the present invention, in the step b), the curing may be preferable in terms of a rapid curing time and an increase in a curing rate, The present invention is not limited thereto.

The ultraviolet ray according to an embodiment of the present invention may have a light emission distribution of 400 nm or less, preferably 150 to 400 nm, more preferably 200 to 380 nm. For example, the ultraviolet rays can be used in a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, a chemical lamp, a black light lamp, a microwave excited mercury lamp, and a metal halide lamp.

The intensity of the light irradiation according to an embodiment of the present invention can be adjusted according to the properties of the required coating film.

As a specific, non-limiting example, the amount of accumulated light useful for the activity of the free radical initiator may be preferably from 10 to 5000 mJ / cm2, more preferably from 200 to 1500 mJ / cm2. When the above-mentioned criterion is satisfied, it is possible to prevent degradation of the cohesive force of the coating film produced by heat generated during the polymerization reaction and the deterioration of the yellowing or transparent substrate, .

Further, in the method for manufacturing a coating film for protecting an automobile glass according to an embodiment of the present invention, the transparent substrate may be treated with plasma before the step a), but the present invention is not limited thereto. Thus, the coating film according to the present invention can further increase the bonding strength with the automobile glass, and the transmittance of light can also be increased.

Hereinafter, the present invention will be described in detail with reference to the following examples. However, the present invention is not limited to the following examples.

Example 1

(1) Coating film composition

130 g of a monofunctional urethane acrylate oligomer (DFCN-27, Negami Chemical; weight average molecular weight = 30,000; hereinafter referred to as "DFCN-27"), 2-ethylhexyl acrylate (Tg = EA "), 16 g of ethoxy-ethoxyethyl acrylate (Sartomer SR 256, Cray Valley, Tg = -56 ° C, hereinafter referred to as" Et- (2-hydroxy-2-methyl-1- [4-1 (methylvinyl) phenyl] propan-1-one] having a weight ratio of 5: 5 g of hydroxy-2-methyl-1-phenylpropan-1-one (Esacure KIP 100, Lamberti SPA) and 2,4,6-trimethylbenzophenone and benzophenone TZT, Lamberti SPA) were mixed to prepare a final coating film composition. The monofunctional urethane acrylate oligomer has a weight average molecular weight of 30,000 and is an ether main chain. Propylene glycol is introduced into a reactive terminal group, and the number of terminal hydroxyl groups (-OH) is one.

(2) Coating film production

The coating film composition was dispersed with a vortex mixer for 5 minutes, and then injected into an injection device equipped with a nozzle. The applied coating film composition was sprayed on an automobile windshield at a pressure of 10 bar for 10 minutes and then irradiated with ultraviolet rays at an intensity of 600 mJ / cm 2 for 30 minutes to prepare a final coating film. The thickness of the cured coating film according to the thickness measurement using an optical microscope was confirmed to be about 500 탆.

Example 2-3

The procedure of Example 1 was repeated except that toluene and ethyl acetate as solvents were added at a weight ratio of 3: 1 to prepare a final coating film composition. The composition of each component was used as shown in Table 1 below.

Examples 4-8

(Trimethoxysilyl) propyl methacrylate (hereinafter referred to as "MPS"), which is a silane coupling agent, was added without adding Et-Et- To prepare a coating film composition. The composition of each component was used as shown in Table 1 below.

Example 9

3- (trimethoxysilyl) propyl methacrylate, which is a silane coupling agent, was prepared in the same manner as in Example 1 to prepare a final coating film composition. The composition of each component was used as shown in Table 1 below.

Examples 10-12

The procedure of Example 1 was repeated except that Et-Et-Et was not added. The composition of each component was used as shown in Table 1 below.

Example 13

The procedure of Example 1 was repeated except that the monofunctional urethane acrylate oligomer was changed to 12.5 parts by weight based on 100 parts by weight of the coating composition to prepare a final coating film composition. The composition of each component was used as shown in Table 1 below.

Examples 14-15

The procedure of Example 1 was repeated except that the silane coupling agent or the silane coupling agent and the surface modified nanoparticles were simultaneously added to prepare a final coating film composition. The composition of each component was used as shown in Table 1 below.

The method of preparing the surface-modified nanoparticles is as follows.

After adding zirconia (2 g, 16.2 mmol) to tetrahydrofuran (50 mL), 3- (trimethoxysilyl) propyl methacrylate (MPS, 0.81 g, 3.2 mmol) was added and sonicated for 30 minutes , And refluxed at 70 DEG C for 24 hours. After cooling to room temperature and centrifugation at 4000 rpm for 20 minutes, surface-modified nanoparticles (hereinafter referred to as "MPS-zirconia") were obtained after washing five times with tetrahydrofuran.

Comparative Example 1

The final coating composition was prepared in the same manner as in Example 1 except that HDDA was not added. The composition of each component was used as shown in Table 1 below.

Comparative Example 2

Except that a bifunctional urethane acrylate oligomer (DFCN-1, Negami Chemical) was added in the same manner as in Example 1 to prepare a final coating film composition. The composition of each component was used as shown in Table 1 below. The bifunctional urethane acrylate oligomer has a weight average molecular weight of 10,000.

[Table 1]

Test Example

The physical properties of the coating films prepared in Examples and Comparative Examples were measured by the following methods, and the results are shown in Table 2 below.

1. Transmittance

The transmittance of light at 500 nm wavelength was measured using a UV-vis spectrophotometer (Shimadzu UV-2550). When the transmittance of the uncoated automotive windshield was taken as 100, the transmittance of the cured coating film on the automotive windshield was expressed in%.

2. Pencil Hardness

The pencil hardness was measured using a 1 Kg load cell from 6B to 9H according to ASTM D3363 to measure the surface hardness of the coating.

3. Tensile strength and elongation

Tensile strength and elongation were calculated by measuring the time at which the specimen was cut by pulling at a crosshead speed of 200 mm / min in a universal test machine according to ASTM D412.

4. Impact strength

And measured at 23 캜 according to ASTM D256 (1/8 inch, Notched Izod).

5. Cohesion

The binding force was measured 5 times through SAICAS (Surface And Interfacial Cutting Analysis System) and the average value was recorded. In SAICAS, the blade of Boron Nitride enters the interface between the coating film and the automobile glass in a static load mode (horizontal velocity: 2 μm / sec, vertical velocity: 0.5 μm / sec, pressure load: 0.5 N) Was changed to 0.2 N to peel the coating film from the automobile glass and the binding force was measured through the force to be measured.

6. Thickness

The coating film was cut out in a size of 1 cm × 1 cm from the top, bottom, left and right sides of the cured coating film on the automobile windshield, and then the thickness and thickness of 10 specimens were measured with an optical microscope. Respectively.

[Table 2]

As shown in Table 2, when a coating film was formed using a monofunctional urethane acrylate oligomer having a hydroxyl group at the terminal, excellent pencil hardness and high adhesion strength, which are advantages of the monofunctional urethane acrylate oligomer, While maintaining a tensile strength of 50 MPa or more.

In addition, as shown in Examples 4 to 8, it was found that the impact strength was improved about twice as much as that in Example 1 due to the high elasticity which is an advantage of the silane coupling agent.

In addition, as shown in Examples 14 to 15, it was confirmed that pencil strength, tensile strength, impact strength, and adhesion were excellent due to high hardness, which is an advantage of surface modified nanoparticles.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Those skilled in the art will recognize that many modifications and variations are possible in light of the above teachings.

Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (5)

A coating film composition for protecting an automobile glass comprising a monofunctional urethane acrylate oligomer, a monofunctional acrylate monomer, a polyfunctional acrylate monomer, and a photoinitiator.
The method according to claim 1,
The monofunctional urethane acrylate oligomer has a hydroxyl group (-OH) at the terminal,
An ester main chain, or a mixture structure thereof,
A coating film composition for protecting glass for automobiles having a weight average molecular weight of 1,000 to 30,000.
The method according to claim 1,
With respect to 100 parts by weight of the coating film composition,
Wherein the monofunctional urethane acrylate oligomer is 30 to 75 parts by weight, the monofunctional acrylate monomer is 5 to 50 parts by weight, the polyfunctional acrylate monomer is 0.1 to 10 parts by weight, and the photoinitiator is 0.1 to 10 parts by weight Coating composition for protecting an automobile glass.
The method according to claim 1,
Wherein the coating film composition further comprises a silane coupling agent represented by the following Formula 1:
[Chemical Formula 1]

Wherein X is a linear or branched C1 to C12 hydrocarbon group or a cyclic C3 to C20 hydrocarbon group having only one or two or more acryl groups and each of R ₁ to R ₃ is independently C1- C5 alkyl.]
A method for manufacturing a coating film for protecting an automobile glass using the coating film composition according to any one of claims 1 to 4,
a) forming a coating film by spraying the coating film composition onto a transparent substrate; And
b) curing the coating film by ultraviolet or electron beam,
Wherein the thickness of the cured coating film is 25 to 1000 mu m.